Collapsible container

ABSTRACT

A collapsible container has four panels that fold down on a base for storage. The base has slide sockets with vertical slots. Front and rear panels pivot on the base with slide hinges received in the slide sockets. The panels are able to slide up and down. A hinge pin has a narrowed waist portion to engage a latch. Left and right panels pivot with snap hinges received in snap sockets on the base. Trunnions, disposed in the snap sockets, are eccentric to increase or decrease the backlash between the snap hinge and the snap socket as the panels pivot. The left and right panels have edge pockets that receive edge fingers on the front and rear panels to hold the container open. The front and rear panels each have an access opening with access doors. Links pivot the access doors on two hinge rods. Locking members wedge the hinge rods in the hinge knuckles. The base has feet with bumper plates having flanges that prevent the container from shifting on an adjacent lower stacked container.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates to the field of folding containers, and more particularly to a—bulk material container having side and end panels pivotally mounted to a base, and able to fold down upon the base. For shipping or storing the empty container, the panels are folded down flat. To open the container for use, the panels are pivoted upright and locked together at the corners. Open containers filled with bulk material can be stacked one upon another. Folded containers can be stacked for efficient shipping and storage. Mixed open and folded containers can also be stacked.

Collapsible containers are known in the prior art, and have taken a variety of configurations in the past. Some examples of collapsible containers are as follows:

Miller, U.S. Pat. No. 5,094,356; Reiland, U.S. Pat. No. 4,775,068; Friedrich, U.S. Pat. No. 4,062,467; Foy, U.S. Pat. No. 4,923,079; and Hoss, U.S. Pat. No. 4,735,330; each disclose a knock down container with opposite side and end panels hinged to a base.

Miller 356 shows a molded plastic base having a floor with a reinforcing grid beneath it. The floor has numerous large pockets requiring cover plates, so that bulk material or finished products will not drop into the pockets. Furthermore, the pockets require a longer pull to open the mold to eject the finished base.

The side and end panels on these prior-art devices are expected to be able to fold into the closed position quickly and easily. Yet, the hinge joints are all made close fitting, so that as the panels are pivoted downward, they may not nest precisely in the base. It might be necessary to “spring” the panels toward one side or the other to fit them all the way down into the base.

The side panels of the prior-art devices are pivotally attached to the base with a slotted hinge, providing “lost motion,” or vertical sliding motion as well as rotation. This allows the side panel to be raised above the end panel, and then lowered vertically to latch fingers on the side panels into pockets on the end panels. This attaches the panels at the corners. Typically, one or more metal pivot pins or rods are inserted into the side panel hinges and fastened with nuts, washers, or the like fasteners on each end. These fasteners can dislodge, allowing the pin to slide out.

Accordingly, there is a need to provide a molded collapsible container having a base with a reinforcing grid on the bottom and a continuous floor so as to minimize the mold pull distance and eliminate pockets in the floor that would trap bulk material.

There is a further need to provide a collapsible container of the type described and that has hinge joints that are close fitting when the panels are open for precise latching of the corners, and that are loose fitting when the panels are folded for easy nesting of the panels in the base.

There is a yet further need to provide a collapsible container of the type described and that has hinge pins that install quickly and need no fasteners to secure the pins.

There is a still further need to provide a collapsible container of the type described and that can be opened and folded quickly and easily.

There is another need to provide a collapsible container of the type described and that can be manufactured cost-effectively in large quantities of high quality.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a collapsible container for use in conveying and storing bulk material and products. A base has a floor, front and rear ends and left and right sides. The base has a wall along the ends and sides, and four corners. The wall projects upward above the floor, which is continuous, with no large openings to trap bulk material and only a few small drain holes.

Front and rear panels each have first, second, top, and bottom edges. The front and rear panels bottom edges are pivotally mounted on the base front and rear ends. The pivotal mounting provides lost motion and allows the panels to be pivoted downward into a folded position on the base, and into an open upright position. Fingers are arrayed along the panel first and second edges. Three slide hinges extend downward from the bottom edges of the panels. Each slide hinge has hooks extending downward and facing alternately inward and outward. The hooks define a transverse passage having a pivot axis. Three slide sockets are provided in each of the base front and rear ends. Each slide socket receives one of the slide hinges. Each slide socket has a pair of opposed, generally vertical slots. A resilient latch extends downward from the bottom edge of the front and rear panels, coextensive with the slide hinge, and between the hooks. A novel hinge pin engages each slide hinge. The hinge pin has a narrowed waist portion to engage the latch. The waist portion retains the hinge pin in the slide hinge. The hinge pin engages the slots to slide upward in the slide socket.

Left and right panels each extend between first, second, top, and bottom edges. The panel bottom edges are pivotally mounted on the base left and right sides. This allows the panels to be pivoted downward into a folded position, and pivoted upward into an open upright position. The panel first and second edges each have an array of pockets. The left and right panel pockets receive the front and rear panel fingers.

Three snap hinges extend downward from the bottom edges of the left and right panels. Three snap sockets are disposed in each of the base left and right sides. Each snap socket receives one of the snap hinges. Each snap socket has a predetermined width. Two novel trunnions project outward from each snap hinge. The trunnions are eccentric to decrease the backlash between the snap hinge and the snap socket with the panels in the open position, to locate the panels precisely. Conversely, the trunnions will increase the backlash with the panels in the closed position, to allow for easy folding of the panels.

Two resilient cantilever members are disposed in each snap socket. The cantilever members will engage and capture the trunnions as the snap hinge is inserted into the snap socket. The cantilever members retain and center the snap hinge in the snap socket.

Front and rear access doors have outer, top, and bottom edges. The outer edges each have an array of plugs. The front and rear panels each have an access opening with an array of receptacles to receive the plugs.

Door pivotal mounting includes a first row of hinge knuckles arrayed along the front and rear panels access opening lower edges. A second row of hinge knuckles is arrayed along the front and rear access doors bottom edges. Links are provided for pivoting the access doors with lost motion. Each link has third and fourth rows of hinge knuckles parallel and spaced apart and having passages. The third and fourth rows of hinge knuckles fit between the first and second rows of hinge knuckles.

Two hinge rods are provided for each link. The hinge rods have a uniform radius and engage the first, second, third, and fourth hinge knuckle passages. Each hinge rod has a novel locking member at one end. The locking member protrudes beyond the hinge rod radius, to wedge tightly in the hinge knuckle passages to retain the hinge rods in the hinge knuckles.

Feet extend downward from the base to a bottom surface to raise the container off a floor. The feet have shoulders to receive the top edges of the panels when the container is open. The shoulders will receive the base wall when the container is folded, to enable containers to be stacked one upon another in both the open and closed conditions. Skid bars are attached to the feet. Bumper plates, mounted on the feet outer edges, have flanges that prevent the container from shifting on an adjacent lower stacked container.

The container base, panels and access doors are molded from either thermoplastic or thermoset resins.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawing, in which:

FIG. 1 is a perspective assembly view of three collapsible containers constructed in accordance with the invention, and stacked one upon another, the topmost container being folded, and the remaining two being open.

FIG. 2 is an exploded perspective assembly view of a collapsible container constructed in accordance with the invention.

FIG. 3 is a partial top plan view of a base of the collapsible container of FIG. 2, showing one half of the front end, one half of the left side, and one quarter of the floor, with the remaining portions being mirror images of those shown.

FIG. 4 is a sectional elevational view of a snap socket of the collapsible container of FIG. 2, taken along lines 44 of FIG. 3.

FIG. 5 is a sectional elevational view of a snap socket of the collapsible container of FIG. 2, taken along lines 5-5 of FIG. 3.

FIG. 6 is a partial bottom plan view of the base, showing the reverse of FIG. 3.

FIG. 7 is a partial sectional elevational view of the base of FIG. 3, taken along lines 7-7 of FIG. 6.

FIG. 8 is a partial inside elevational view of a right or left panel of the collapsible container of FIG. 2, showing half of the panel.

FIG. 9 is an edge elevational view of the panel of FIG. 8.

FIG. 10 is a top view of the panel of FIG. 8.

FIG. 11 is a sectional plan view of a snap hinge of the panel of FIG. 8, taken along lines 11-11 of FIG. 8.

FIG. 12 is a sectional elevational view of the snap hinge of the panel of FIG. 8, taken along lines 12-12 of FIG. 8.

FIG. 13 is a left or right elevational view of the collapsible container of FIG. 2.

FIG. 14 is a partial perspective view of a snap hinge of the collapsible container of FIG. 2, shown with the panel folded.

FIG. 15 is a side elevational view of the snap hinge of FIG. 14, taken along lines 15-15 of FIG. 14.

FIG. 16 is a partial perspective view of the snap hinge of FIG. 14, shown with the panel open.

FIG. 17 is a side elevational view of the snap hinge of FIG. 16, taken along lines 17-17 of FIG. 16.

FIG. 18 is a partial outside elevational view of a front or rear panel of the collapsible container of FIG. 2, showing half of the panel.

FIG. 19 is an edge elevational view of the panel of FIG. 18, taken along lines 19-19 of FIG. 18.

FIG. 20 is a sectional elevational view of the panel of FIG. 18, taken along lines 20-20 of FIG. 18.

FIG. 21 is a sectional elevational view of the panel of FIG. 18, taken along lines 21-21 of FIG. 18.

FIG. 22 is a sectional elevational view of the panel of FIG. 18, taken along lines 22-22 of FIG. 18.

FIG. 23 is a sectional plan view of a corner of the collapsible container of FIG. 2, taken along lines 23-23 of FIG. 13.

FIG. 24 is a front elevational view of a hinge pin of the collapsible container of FIG. 2.

FIG. 25 is an exploded, partial perspective view of a slide hinge, slide socket, and hinge pin of the collapsible container of FIG. 2.

FIG. 26 is a front elevational view of the slide hinge of FIG. 25, taken along lines 26-26 of FIG. 25.

FIG. 27 a is a sectional elevational view of the slide hinge of FIG. 25, taken along lines 27 a-27 a of FIG. 26.

FIG. 27 b is a sectional plan view of the slide hinge of FIG. 25, taken along lines 27 b-27 b of FIG. 26.

FIG. 28 is a sectional elevational view of the slide hinge of FIG. 25, taken along lines 28-28 of FIG. 26.

FIG. 29 is a sectional elevational view of the slide hinge of FIG. 25, taken along lines 29-29 of FIG. 26.

FIG. 30 is an elevational assembly view of a slide hinge, slide socket, and hinge pin of the collapsible container of FIG. 2.

FIG. 31 is a sectional elevational view of the slide hinge, slide socket, and hinge pin of FIG. 30, taken along lines 31-31 of FIG. 30.

FIG. 32 is a sectional elevational view of the slide hinge, slide socket, and hinge pin of FIG. 30, taken along lines 32-32 of FIG. 30.

FIG. 33 is a partial outside elevational view of an access door of the collapsible container of FIG. 2, showing half of the door.

FIG. 34 is a side sectional elevational view of the panel of FIG. 33, taken along lines 34-34 of FIG. 33.

FIG. 35 is a side sectional elevational view of the panel of FIG. 33, taken along lines 35-35 of FIG. 33.

FIG. 36 is a partial side sectional elevational view of the panel of FIG. 33, taken along lines 36-36 of FIG. 33.

FIG. 37 is a partial sectional plan view of the panel of FIG. 33, taken along lines 37-37 of FIG. 33.

FIG. 38 is a partial perspective view of a door hinge assembly of the collapsible container of FIG. 2, showing the first, second, third, and fourth hinge knuckles, the access door bottom edge, the link, and two hinge rods.

FIG. 39 is a top plan view of the link of the door hinge assembly of FIG. 38.

FIG. 40 is a side sectional elevational view of the link of FIG. 39, taken along lines 4040 of FIG. 39.

FIG. 41 is a side sectional elevational view of the link of FIG. 39, taken along lines 41-41 of FIG. 39.

FIG. 42 is a top plan view of the hinge rod of the door hinge assembly of FIG. 38.

FIG. 43 is a top plan view of a skid bar of the collapsible container of FIG. 2.

FIG. 44 is a side elevational view of the skid bar of FIG. 43.

FIG. 45 is an end elevational view of the skid bar of FIG. 43.

FIG. 46 is a front elevational view of a bumper plate of the collapsible container of FIG. 2.

FIG. 47 is a top plan view of the bumper plate of FIG. 46.

FIG. 48 is a perspective view of the bumper plate of FIG. 46.

FIG. 49 is a perspective assembly view of the collapsible container of FIG. 2, showing the container in the folded position with the left panel being opened.

FIG. 50 is a perspective assembly view of the collapsible container of FIG. 2, showing the container in the partly opened position with the rear panel being opened.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing, and especially to FIGS. 1-32 thereof, a collapsible container is shown at 50, and is for use in conveying and storing bulk material and products. A base 52 extends between opposite front 54 and rear 56 ends, and between opposite left 58 and right 60 sides. The base 52 has a floor 62 extending between the base front 54 and rear 56 ends and between the base left 58 and right 60 sides. The base 52 has a wall 64 extending along the front 54 and rear 56 ends and the left 58 and right 60 sides. The wall 64 projects upward above the floor 62. The base 52 has four corners 66 where the ends meet the sides. FIG. 3 is a top plan view of the base, showing the floor 62 being continuous, with no large openings to trap bulk material, and only a few small drain holes 63. FIG. 6 is a bottom view of FIG. 3, showing the reinforcing structure.

A front panel 68 extends between opposite first 70 and second 72 edges and between opposite top 74 and bottom 76 edges. The front panel 68 has inner 78 and outer 80 surfaces. The front panel bottom edge 76 is pivotally mounted on the base front end 54. The pivotal mounting provides lost motion. Specifically, lost motion allows the panel to translate, or move in a straight line upward and downward. The pivotal mounting allows the front panel 68 to be pivoted downward into a folded position adjacent the base floor 62, and pivoted upward into an open upright position. The front panel first 70 and second 72 edges each have a latching means, specifically a plurality of fingers 82 arrayed in a linear spaced relationship along the edges.

A rear panel 84 extends between opposite first 86 and second 88 edges and between opposite top 90 and bottom 92 edges. The rear panel 84 has inner 94 and outer 96 surfaces. The rear panel bottom edge 92 is pivotally mounted on the base rear end 56, in a manner identical to that of the front panel 70. The pivotal mounting provides lost motion as well as pivotal motion. The rear panel first 86 and second 88 edges each have a plurality of fingers 98 arrayed in a linear spaced relationship along the edges.

At least one, and preferably three slide hinges 100 extend downward from the bottom edges 76 and 92 of each of the front 68 and rear 84 panels, respectively. Each slide hinge 100 has a plurality of hooks 102 a and 102 b extending downward and facing alternately inward 102 a and outward 102 b. The hooks 102 a and 102 b define a transverse passage 104 having a pivot axis about which the slide hinge 100 pivots. At least one, and preferably three slide sockets 106 are provided in each of the base front 54 and rear 56 ends. Each slide socket 106 is adapted to receive one of the slide hinges 100. Each slide socket 106 has a pair of opposed, generally vertical slots 108. A resilient latch 110 extends downward in a cantilever from the bottom edge 76 and 92 of each of the front 68 and rear 84 panels. The latch 110 is coextensive with the slide hinge 100. The latch 110 is disposed between adjacent hooks 102 a and is centrally located in the slide hinge 100, as shown in FIG. 26. A novel hinge pin 112 is adapted to slidingly engage each slide hinge 100 along the pivot axis. The hinge pin 112 has a narrowed waist portion 114 adapted to engage the latch 110, which is biased toward the waist portion 114. The waist portion 114 retains the hinge pin 112 in the slide hinge 100. The hinge pin 112 has a bevel 113 on either end to smoothly engage the latch 110. The hinge pin 112 is adapted to engage the slots 108 so as to allow the slide hinge 100 to slide upward and downward in the slide socket, providing lost motion. At the same time the hinge pin 112 allows the slide hinge 100, and thus the front 68 and rear 84 panels, to pivot.

To assemble the front 68 and rear 84 panels onto the base 52, the slide hinges 100 will be inserted downward into the slide sockets 106. The pivot axis will be aligned with the slots 108. The hinge pin 112 will be inserted axially through one of the slots 108 and will then slide along the transverse passage 104, which passes through the hooks 102 a and 102 b. The hinge pin 112 will deflect the latch 110 resiliently away from the pivot axis. The waist portion 114 will align with the latch 110. This will allow the latch 110 to flex with bias toward the pivot axis and into the waist portion 114. The latch 110 will retain the hinge pin 112 in the slide hinge 100. The hinge pin 112 is long enough to project outward through both of the opposing slots 108. This allows the slide hinge 100 to rotate and translate with respect to the slide socket 106.

A left panel 116 extends between opposite first 118 and second 120 edges and between opposite top 122 and bottom 124 edges. The left panel 116 has inner 126 and outer 128 surfaces. The left panel bottom edge 124 is pivotally mounted on the base left side 58. This allows the left panel 116 to be pivoted downward into a folded position adjacent the base floor 62, and pivoted upward into an open upright position. The left panel first 118 and second 120 edges each have a latching means, specifically a plurality of pockets 130 arrayed in a linear spaced relationship along the edges. The left panel first and second edge pockets 130 are adapted to receive the rear panel second edge fingers 98 and the front panel first edge fingers 82, respectively.

A right panel 132 extends between opposite first 134 and second 136 edges and between opposite top 138 and bottom 140 edges. The right panel has inner 142 and outer 144 surfaces. The right panel bottom edge 140 is pivotally mounted on the base right side 60. This allows the right panel 132 to be pivoted downward into a folded position adjacent the base floor 62, and pivoted upward into an open upright position. The right panel first 134 and second 136 edges each have a plurality of pockets 146 arrayed in a linear spaced relationship along the edges. The right panel first and second edge pockets 146 are adapted to receive the front panel second edge fingers 82 and the rear panel first edge fingers 98, respectively.

At least one, and preferably three snap hinges 148 extend downward from the bottom edges 124 and 140 of each of the left 116 and right 132 panels, respectively. At least one, and preferably three snap sockets 150 are disposed in each of the base left 58 and right 60 sides. Each snap socket 150 is adapted to receive one of the snap hinges 148. Each snap socket 150 has a predetermined width, W in FIG. 15. Two novel trunnions 152 project outward from each snap hinge 148. The trunnions 152 are eccentric, meaning they are non-circular, such as egg-shaped, or elliptical, or oval. They can also be circular, but off-center with respect to the pivotal center. In any case, the eccentricity of the trunnions 152 serves to decrease the backlash, or clearance, between the snap hinge 148 and the snap socket 150 with the panels in the open position, to locate the panels with precision. Conversely, the trunnions 152 will increase the backlash with the panels in the closed position. This allows yawing the panels from side to side for easy folding of the panels.

Two resilient cantilever members 154 are disposed in each snap socket 150. Thus the cantilever members 154 will engage the trunnions 152 as the snap hinge 148 is inserted downward into the snap socket 150. The trunnions 152 will deflect the cantilever members 154 resiliently away from the snap hinge 148 until the trunnions 152 pass the cantilever members 154. The cantilever members 154, under bias, are allowed to flex inward toward one another so as to capture the trunnions 152. The cantilever members 154 retain the snap hinge 148 in the snap socket 150. The cantilever members 154 pinch the snap hinge 148 between them, and thereby hold the snap hinge 148 generally centered in the snap socket 150.

Referring now to FIGS. 33-48, as well as FIGS. 1-32, front and rear access doors 156 extend between opposite outer edges 158 and between opposite top 160 and bottom 162 edges. The front and rear access doors 156 each have inner 164 and outer 166 surfaces. The outer edges 158 each have a plurality of plugs 168 arrayed in a linear spaced relationship along the outer edges 158. The front 68 and rear 84 panels each have an access opening 170 extending between opposite outer edges 172 and between a lower edge 174 and the panel top edges 74 and 90. Each access opening 170 has a plurality of receptacles 176 arrayed in a linear spaced relationship along the outer edges 172. The receptacles 176 are adapted to receive the plugs 168.

Door pivotal means is provided for pivotal mounting of the front and rear access doors 156 on the front 68 and rear 84 panels, respectively. The door pivotal means provides lost motion. Specifically, a first row of hinge knuckles 178 is arrayed in a linear spaced relationship along the front 68 and rear 84 panels access opening lower edges 174. The first row of hinge knuckles 178 has passages therethrough 180 in linear alignment defining a first door axis. A second row of hinge knuckles 182 is arrayed in a linear spaced relationship along the front and rear access doors 156 bottom edges 162. The second row of hinge knuckles 182 has passages 184 therethrough in linear alignment defining a second door axis.

A front and a rear link 186 are provided for the front and rear access doors 156. Each link 186 has a third row of hinge knuckles 188 arrayed in a linear spaced relationship along the link 186. The third row of hinge knuckles 188 has passages 190 therethrough in linear alignment defining a third door axis. Each link 186 has a fourth row of hinge knuckles 192 arrayed in a linear spaced relationship along the link 186. The fourth row of hinge knuckles 192 has passages 194 therethrough in linear alignment defining a fourth door axis. The third door axis and the fourth door axis are parallel and spaced apart. The third 188 and fourth 192 rows of hinge knuckles are adapted to fit between the first 178 and second 182 rows of hinge knuckles, respectively. The first door axis is collinear with the third door axis, and the second door axis is collinear with the fourth door axis.

Two hinge rods 196 are provided for each link 186. The hinge rods 196 are straight and of a uniform predetermined radius adapted for close sliding engagement with the first 180, second 1.84, third 190, and fourth 194 hinge knuckle passages. Each hinge rod 196 has a novel locking member 198 at one end. The locking member 198 protrudes beyond the predetermined radius, so as to wedge tightly in the hinge knuckle passages. In this manner, the hinge rods 196 are thereby retained in the hinge knuckles 178, 182, 188, and 192.

To gain access to the containers 50, the front and rear access doors 156 will be pivoted downward into an open position adjacent the front 68 and rear 84 panels respectively. In this open position, access doors 156 will depend from the access opening lower edge 174. To close the access doors 156, they will be pivoted upward into an upright closed position in the access opening 170, with the plugs 168 juxtaposed over the receptacles 176. The access doors 156 will then be lowered until the plugs 168 are received in the receptacles 176, thereby latching the access doors closed.

A plurality of feet 200 extends downward from the base 52 to a bottom surface 202 so as to raise the container 50 off a floor. Preferably, the container 50 has feet 200 on each corner, and between corners, and centralized under the base 52. The feet 200 have an outer edge 204 with a shoulder 206 adapted to receive the top edges 74, 90, 122, and 138, of the front, rear, left, and right panels respectively, when the container is open. The shoulder 206 is also adapted to receive the base wall 64 when the container 50 is folded, so as to enable containers to be stacked one upon another in both the open and closed conditions. A plurality of skid bars 208 is attached to the bottom surface 202 of the feet 200. The skid bars 208 have a cross-sectional shape, shown in FIG. 45. Each of the feet 200 has a shape in its bottom surface matching the cross-sectional shape so as to receive the skid bars 208.

A bumper plate 210 is mounted on the outer edge 204 of four of the feet 200 at the corners 66 of the base 52. The bumper plate 210 is generally L-shaped and extends between opposite upper 218 and lower 220 edges. The bumper plate 210 has an inner surface 222 for mounting against the feet 200, and an opposite outer surface 224. The bumper plate 210 has a flange 226 extending outward and downward from the lower edge 220. The bumper plate flange 226 mounted on a first container 50 will overlap a second container stacked beneath it, so as to prevent lateral shifting of the first container.

In the preferred embodiment, the base 52, front panel 68, rear panel 84, left panel 116, right panel 132, front access door 156, and rear access door 156 are molded from a polymeric material selected from the group consisting of thermoplastic resins and thermoset resins.

Turning now to FIGS. 49 and 50, to open the container 50, the left 116 and right 132 panels will be pivoted from a folded position lying generally flat adjacent the base 52, to an upright position as shown by arrow 212 in FIG. 49. The front 68 and rear 84 panels will be pivoted from a folded position lying generally flat adjacent the base 52, to an upright position as shown by arrow 214 in FIG. 50. At the same time the front 68 and rear 84 panels will be raised upward as shown by arrow 216 in FIG. 50. The fingers 82 and 98 of the front and rear panels will be juxtaposed over corresponding pockets 130 and 146 of the left and right panels. The front 68 and rear 84 panels will be lowered so that the fingers will be received in the pockets, thereby latching the panels at the edges thereof in the open position.

Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications that will come within the scope of the appended claims is reserved.

PART NO. DESCRIPTION  50 collapsible container  52 base  54 base front end  56 base rear end  58 base left side  60 base right side  62 floor  63 floor drain holes  64 wall  66 corners  68 front panel  70 front panel first edge  72 front panel second edge  74 front panel top edge  76 front panel bottom edge  78 front panel inner surface  80 front panel outer surface  82 front panel fingers  84 rear panel  86 rear panel first edge  88 rear panel second edge  90 rear panel top edge  92 rear panel bottom edge  94 rear panel inner surface  96 rear panel outer surface  98 rear panel fingers 100 slide hinge  102a slide hinge hooks inward  102b slide hinge hooks outward 104 slide hinge transverse passage 106 slide socket 108 vertical slots 110 latch 112 hinge pin 113 hinge pin beveled end 114 waist portion 116 left panel 118 left panel first edge 120 left panel second edge 122 left panel top edge 124 left panel bottom edge 126 left panel inner surface 128 left panel outer surface 130 left panel pockets 132 right panel 134 right panel first edge 136 right panel second edge 138 right panel top edge 140 right panel bottom edge 142 right panel inner surface 144 right panel outer surface 146 right panel pockets 148 snap hinges 150 snap sockets 152 trunnions 154 cantilever members 156 access doors 158 access doors outer edges 160 access doors top edge 162 access doors bottom edge 164 access doors inner surface 166 access doors outer surface 168 plugs 170 access opening 172 access opening outer edges 174 access opening lower edge 176 receptacles 178 first row hinge knuckles 180 first row passages 182 second row hinge knuckles 184 second row passages 186 link 188 third row hinge knuckles 190 third row passages 192 fourth row hinge knuckles 194 fourth row passages 196 hinge rod 198 locking member 200 feet 202 bottom surface 204 outer edge 206 shoulder 208 skid bar 210 bumper plate 212 left and right pivot arrow 214 front and rear pivot arrow 216 upward arrow 218 bumper plate upper edge 220 bumper plate lower edge 222 bumper plate inner surface 224 bumper plate outer surface 226 bumper plate flange 

1. A collapsible container comprising: a base extending between opposite front and rear ends, and between opposite left and right sides, the base having a floor extending between the front and rear ends and the left and right sides, the base having a wall extending along the front and rear ends and the left and right sides, the wall projecting upward above the floor, the base having four corners where the ends meet the sides; a front panel extending between opposite first and second edges and between opposite top and bottom edges, the front panel having inner and outer surfaces; front pivotal means for pivotal mounting of the front panel bottom edge on the base front end, the front pivotal means allowing the front panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; a rear panel extending between opposite first and second edges and between opposite top and bottom edges, the rear panel having inner and outer surfaces; rear pivotal means for pivotal mounting of the rear panel bottom edge on the base rear end, the rear pivotal means allowing the rear panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; a left panel extending between opposite first and second edges and between opposite top and bottom edges, the left panel having inner and outer surfaces; left pivotal means for pivotal mounting of the left panel bottom edge on the base left side, the left pivotal means allowing the left panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; a right panel extending between opposite first and second edges and between opposite top and bottom edges, the right panel having inner and outer surfaces; right pivotal means for pivotal mounting of the right panel bottom edge on the base right side, the right pivotal means allowing the right panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; Latching means for latching adjacent edges of the front, rear, left, and right panels together in the open position; a plurality of feet extending downward from the base to a bottom surface so as to raise the container off a floor, the feet having an outer edge with a shoulder adapted to receive the top edges of the front, rear, left, and right panels when the container is open, and to receive the base wall when the container is folded, so as to enable containers to be stacked one upon another in both the open and closed positions; and a bumper plate mounted on the outer edge of each of four of the feet at the corners of the base, the bumper plate being generally L-shaped and extending between opposite upper and lower edges, the bumper plate having an inner surface for mounting against the feet, and an opposite outer surface, the bumper plate having a flange extending outward and downward from the lower edge, the flange being adapted to overlap an adjacent lower stacked container, so as to prevent lateral shifting of a stacked container.
 2. The collapsible container of claim 1, wherein the left and right pivotal means further comprises: at least one snap hinge extending downward from the bottom edge of each of the left and right panels; at least one snap socket in each of the base left and right sides, each snap socket being adapted to receive one of each snap hinge, each snap socket having a predetermined width; two trunnions projecting outward from each snap hinge, the trunnions being eccentric, so as to decrease the backlash between the snap hinge and the snap socket with the panels in the open position for precise positioning of the panels, and to increase the backlash in the closed position for easy folding of the panels; and two resilient cantilever members disposed in each snap socket, so that the cantilever members will engage the trunnions as the snap hinge is inserted downward into the snap socket, the trunnions will deflect the cantilever members resiliently away from the snap hinge until the trunnions pass the cantilever members, allowing the cantilever members to flex inward toward one another so as to capture the trunnions and retain the snap hinge in the snap socket and to hold the snap hinge generally centered in the snap socket.
 3. The collapsible container of claim 1, wherein the front and rear pivotal means further comprises: at least one slide hinge extending downward from the bottom edge of each of the front and rear panels, each slide hinge having a plurality of hooks extending downward and facing alternately inward and outward, the hooks defining a transverse passage having a pivot axis about which the slide hinge pivots; at least one slide socket in each of the base front and rear ends, each slide socket being adapted to receive one of each slide hinge, each slide socket having a pair of opposed, generally vertical slots for providing lost motion; a resilient latch extending downward in a cantilever from the bottom edge of each of the front and rear panels coextensively with the slide hinge, and disposed between the hooks; and a hinge pin adapted to slidingly engage each slide hinge along the pivot axis, the hinge pin having a narrowed waist portion adapted to engage the latch so as to retain the hinge pin in the slide hinge, the hinge pin being adapted to engage the slots so as to allow the slide hinge to slide upward in the slide socket as well as pivot; so that the slide hinge will be inserted downward into the slide socket, the pivot axis will be aligned with the slots, the hinge pin will be inserted axially through one of the slots and pass through the hooks, the hinge pin will deflect the latch resiliently away from the pivot axis, the waist portion will align with the latch, allowing the latch to flex with bias toward the pivot axis into the waist portion so as to retain the hinge pin in the slide hinge, and the hinge pin will pass through the opposing slot, allowing the slide hinge to rotate and translate with respect to the slide socket.
 4. The collapsible container of claim 1, wherein the latching means further comprises: the front panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; the rear panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; the left panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the left panel first and second edge pockets being adapted to receive the rear panel second edge fingers and the front panel first edge fingers, respectively; and the right panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the right panel first and second edge pockets being adapted to receive the front panel second edge fingers and the rear panel first edge fingers, respectively; so that to open the container, the left and right panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, the front and rear panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, and at the same time will be raised upward so that the fingers of the front and rear panels will be juxtaposed over corresponding pockets of the left and right panels, the front and rear panels will be lowered so that the fingers will be received in the pockets, thereby latching the panels at the edges thereof in the open position.
 5. The collapsible container of claim 1, further comprising: front and rear access doors extending between opposite outer edges and between opposite top and bottom edges, the front and rear access doors each having inner and outer surfaces, the outer edges each having a plurality of plugs arrayed in a linear spaced relationship along the outer edges; the front and rear panels each having an access opening extending between opposite outer edges and between a lower edge and the panel top edge, each access opening having a plurality of receptacles arrayed in a linear spaced relationship along the outer edges, the receptacles being adapted to receive the plugs; and door pivotal means for pivotal mounting of the front and rear access doors on the front and rear panels, respectively, the door pivotal means providing lost motion; so that the front and rear access doors will be pivoted downward into an open position adjacent the front and rear panels respectively, and depending from the access opening lower edge, and will be pivoted upward into an upright closed position in the access opening, with the plugs juxtaposed over the receptacles, and will be lowered until the plugs are received in the receptacles, thereby latching the access doors closed.
 6. The collapsible container of claim 5, wherein the door pivotal means further comprises: a first row of hinge knuckles arrayed in a linear spaced relationship along the front and rear panels access opening lower edges, the first row of hinge knuckles having passages therethrough in linear alignment defining a first door axis; a second row of hinge knuckles arrayed in a linear spaced relationship along the front and rear access doors bottom edges, the second row of hinge knuckles having passages therethrough in linear alignment defining a second door axis; a front link and a rear link, each link having a third row of hinge knuckles arrayed in a linear spaced relationship along the link, the third row of hinge knuckles having passages therethrough in linear alignment defining a third door axis, each link having a fourth row of hinge knuckles arrayed in a linear spaced relationship along the link, the fourth row of hinge knuckles having passages therethrough in linear alignment defining a fourth door axis, the third door axis and the fourth door axis being parallel and spaced apart, the third and fourth rows of hinge knuckles being adapted to fit between the first and second rows of hinge knuckles, respectively, with the first door axis collinear with the third door axis, and the second door axis collinear with the fourth door axis; and two hinge rods for each link, the hinge rods being straight and of a uniform predetermined radius adapted for close sliding engagement with the first, second, third, and fourth hinge knuckle passages, each hinge rod having a locking member at one end, the locking member protruding beyond the predetermined radius, so as to wedge tightly in the hinge knuckle passages, thereby retaining the hinge rods in the hinge knuckles.
 7. The collapsible container of claim 5, wherein the base, front panel, rear panel, left panel, right panel, front access door, and rear access door are molded from a polymeric material selected from the group consisting of thermoplastic resins and thermoset resins.
 8. The collapsible container of claim 1, further comprising: a plurality of skid bars attached to the bottom surface of the feet, the skid bars having a cross-sectional shape; and each of the feet having a shape in its bottom surface matching the cross-sectional shape so as to receive the skid bars.
 9. A collapsible container comprising: a base extending between opposite front and rear ends, and between opposite left and right sides, the base having a floor extending between the front and rear ends and the left and right sides, the base having a wall extending along the front and rear ends and the left and right sides, the wall projecting upward above the floor, the base having four corners where the ends meet the sides; a front panel extending between opposite first and second edges and between opposite top and bottom edges, the front panel having inner and outer surfaces, the front panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; front pivotal means for pivotal mounting of the front panel bottom edge on the base front end, the front pivotal means providing lost motion, the front pivotal means allowing the front panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; a rear panel extending between opposite first and second edges and between opposite top and bottom edges, the rear panel having inner and outer surfaces, the rear panel bottom edge being pivotally mounted on the base rear end, the rear panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; rear pivotal means for pivotal mounting of the rear panel bottom edge on the base rear end, the rear pivotal means providing lost motion, the rear pivotal means allowing the rear panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position; a left panel extending between opposite first and second edges and between opposite top and bottom edges, the left panel having inner and outer surfaces, the left panel bottom edge being pivotally mounted on the base left side, allowing the left panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the left panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the left panel first and second edge pockets being adapted to receive the rear panel second edge fingers and the front panel first edge fingers, respectively; a right panel extending between opposite first and second edges and between opposite top and bottom edges, the right panel having inner and outer surfaces, the right panel bottom edge being pivotally mounted on the base right side, allowing the right panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the right panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the right panel first and second edge pockets being adapted to receive the front panel second edge fingers and the rear panel first edge fingers, respectively; at least one snap hinge extending downward from the bottom edge of each of the left and right panels; at least one snap socket in each of the base left and right sides, each snap socket being adapted to receive one of each snap hinge, each snap socket having a predetermined width; two trunnions projecting outward from each snap hinge, the trunnions being eccentric, so as to decrease the backlash between the snap hinge and the snap socket with the panels in the open position for precise positioning of the panels, and to increase the backlash in the closed position for easy folding of the panels; and two resilient cantilever members disposed in each snap socket, so that the cantilever members will engage the trunnions as the snap hinge is inserted downward into the snap socket, the trunnions will deflect the cantilever members resiliently away from the snap hinge until the trunnions pass the cantilever members, allowing the cantilever members to flex inward toward one another so as to capture the trunnions and retain the snap hinge in the snap socket and to hold the snap hinge generally centered in the snap socket; and that to open the container, the left and right panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, the front and rear panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, and at the same time will be raised upward so that the fingers of the front and rear panels will be juxtaposed over corresponding pockets of the left and right panels, the front and rear panels will be lowered so that the fingers will be received in the pockets, thereby latching the panels at the edges thereof in the open position.
 10. The collapsible container of claim 9, wherein the front and rear pivotal means further comprises: at least one slide hinge extending downward from the bottom edge of each of the front and rear panels, each slide hinge having a plurality of hooks extending downward and facing alternately inward and outward, the hooks defining a transverse passage having a pivot axis about which the slide hinge pivots; at least one slide socket in each of the base front and rear ends, each slide socket being adapted to receive one of each slide hinge, each slide socket having a pair of opposed, generally vertical slots for providing lost motion; a resilient latch extending downward in a cantilever from the bottom edge of each of the front and rear panels coextensively with the slide hinge, and disposed between the hooks; and a hinge pin adapted to slidingly engage each slide hinge along the pivot axis, the hinge pin having a narrowed waist portion adapted to engage the latch so as to retain the hinge pin in the slide hinge, the hinge pin being adapted to engage the slots so as to allow the slide hinge to slide upward in the slide socket as well as pivot; so that the slide hinge will be inserted downward into the slide socket, the pivot axis will be aligned with the slots, the hinge pin will be inserted axially through one of the slots and pass through the hooks, the hinge pin will deflect the latch resiliently away from the pivot axis, the waist portion will align with the latch, allowing the latch to flex with bias toward the pivot axis into the waist portion so as to retain the hinge pin in the slide hinge, and the hinge pin will pass through the opposing slot, allowing the slide hinge to rotate and translate with respect to the slide socket.
 11. The collapsible container of claim 9, further comprising: front and rear access doors extending between opposite outer edges and between opposite top and bottom edges, the front and rear access doors each having inner and outer surfaces, the outer edges each having a plurality of plugs arrayed in a linear spaced relationship along the outer edges; the front and rear panels each having an access opening extending between opposite outer edges and between a lower edge and the panel top edge, each access opening having a plurality of receptacles arrayed in a linear spaced relationship along the outer edges, the receptacles being adapted to receive the plugs; and door pivotal means for pivotal mounting of the front and rear access doors on the front and rear panels, respectively, the door pivotal means providing lost motion; so that the front and rear access doors will be pivoted downward into an open position adjacent the front and rear panels respectively, and depending from the access opening lower edge, and will be pivoted upward into an upright closed position in the access opening, with the plugs juxtaposed over the receptacles, and will be lowered until the plugs are received in the receptacles, thereby latching the access doors closed.
 12. The collapsible container of claim 11, wherein the door pivotal means further comprises: a first row of hinge knuckles arrayed in a linear spaced relationship along the front and rear panels access opening lower edges, the first row of hinge knuckles having passages therethrough in linear alignment defining a first door axis; a second row of hinge knuckles arrayed in a linear spaced relationship along the front and rear access doors bottom edges, the second row of hinge knuckles having passages therethrough in linear alignment defining a second door axis; a front link and a rear link, each link having a third row of hinge knuckles arrayed in a linear spaced relationship along the link, the third row of hinge knuckles having passages therethrough in linear alignment defining a third door axis, each link having a fourth row of hinge knuckles arrayed in a linear spaced relationship along the link, the fourth row of hinge knuckles having passages therethrough in linear alignment defining a fourth door axis, the third door axis and the fourth door axis being parallel and spaced apart, the third and fourth rows of hinge knuckles being adapted to fit between the first and second rows of hinge knuckles, respectively, with the first door axis collinear with the third door axis, and the second door axis collinear with the fourth door axis; and two hinge rods for each link, the hinge rods being straight and of a uniform predetermined radius adapted for close sliding engagement with the first, second, third, and fourth hinge knuckle passages, each hinge rod having a locking member at one end, the locking member protruding beyond the predetermined radius, so as to wedge tightly in the hinge knuckle passages, thereby retaining the hinge rods in the hinge knuckles.
 13. The collapsible container of claim 11, wherein the base, front panel, rear panel, left panel, right panel, front access door, and rear access door are molded from a polymeric material selected from the group consisting of thermoplastic resins and thermoset resins.
 14. The collapsible container of claim 9, further comprising a plurality of feet extending downward from the base to a bottom surface so as to raise the container off a floor, the feet having an outer edge with a shoulder adapted to receive the top edges of the front, rear, left, and right panels when the container is open, and to receive the base wall when the container is folded, so as to enable containers to be stacked one upon another in both the open and closed positions.
 15. The collapsible container of claim 14, further comprising: a plurality of skid bars attached to the bottom surface of the feet, the skid bars having a cross-sectional shape; and each of the feet having a shape in its bottom surface matching the cross-sectional shape so as to receive the skid bars.
 16. The collapsible container of claim 14, further comprising a bumper plate mounted on the outer edge of each of four of the feet at the corners of the base, the bumper plate being generally L-shaped and extending between opposite upper and lower edges, the bumper plate having an inner surface for mounting against the feet, and an opposite outer surface, the bumper plate having a flange extending outward and downward from the lower edge, the flange being adapted to overlap an adjacent lower stacked container, so as to prevent lateral shifting of a stacked container.
 17. A collapsible container comprising: a base extending between opposite front and rear ends, and between opposite left and right sides, the base having a floor extending between the front and rear ends and the left and right sides, the base having a wall extending along the front and rear ends and the left and right sides, the wall projecting upward above the floor, the base having four corners where the ends meet the sides; a front panel extending between opposite first and second edges and between opposite top and bottom edges, the front panel having inner and outer surfaces, the front panel bottom edge being pivotally mounted on the base front end, the pivotal mounting providing lost motion and allowing the front panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the front panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; a rear panel extending between opposite first and second edges and between opposite top and bottom edges, the rear panel having inner and outer surfaces, the rear panel bottom edge being pivotally mounted on the base rear end, the pivotal mounting providing lost motion and allowing the rear panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the rear panel first and second edges each having a plurality of fingers arrayed in a linear spaced relationship along the edges; at least one slide hinge extending downward from the bottom edge of each of the front and rear panels, each slide hinge having a plurality of hooks extending downward and facing alternately inward and outward, the hooks defining a transverse passage having a pivot axis about which the slide hinge pivots; at least one slide socket in each of the base front and rear ends, each slide socket being adapted to receive one of each slide hinge, each slide socket having a pair of opposed, generally vertical slots for providing the lost motion; a resilient latch extending downward in a cantilever from the bottom edge of each of the front and rear panels coextensively with the slide hinge, and disposed between the hooks; a hinge pin adapted to slidingly engage each slide hinge along the pivot axis, the hinge pin having a narrowed waist portion adapted to engage the latch so as to retain the hinge pin in the slide hinge, the hinge pin being adapted to engage the slots so as to allow the slide hinge to slide upward in the slide socket as well as pivot; so that the slide hinge will be inserted downward into the slide socket, the pivot axis will be aligned with the slots, the hinge pin will be inserted axially through one of the slots and pass through the hooks, the hinge pin will deflect the latch resiliently away from the pivot axis, the waist portion will align with the latch, allowing the latch to flex with bias toward the pivot axis into the waist portion so as to retain the hinge pin in the slide hinge, and the hinge pin will pass through the opposing slot, allowing the slide hinge to rotate and translate with respect to the slide socket; a left panel extending between opposite first and second edges and between opposite top and bottom edges, the left panel having inner and outer surfaces, the left panel bottom edge being pivotally mounted on the base left side, allowing the left panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the left panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the left panel first and second edge pockets being adapted to receive the rear panel second edge fingers and the front panel first edge fingers, respectively; a right panel extending between opposite first and second edges and between opposite top and bottom edges, the right panel having inner and outer surfaces, the right panel bottom edge being pivotally mounted on the base right side, allowing the right panel to be pivoted downward into a folded position adjacent the base floor, and pivoted upward into an open upright position, the right panel first and second edges each having a plurality of pockets arrayed in a linear spaced relationship along the edges, the right panel first and second edge pockets being adapted to receive the front panel second edge fingers and the rear panel first edge fingers, respectively; at least one snap hinge extending downward from the bottom edge of each of the left and right panels; at least one snap socket in each of the base left and right sides, each snap socket being adapted to receive one of each snap hinge, each snap socket having a predetermined width; two trunnions projecting outward from each snap hinge, the trunnions being eccentric, so as to decrease the backlash between the snap hinge and the snap socket with the panels in the open position for precise positioning of the panels, and to increase the backlash in the closed position for easy folding of the panels; two resilient cantilever members disposed in each snap socket, so that the cantilever members will engage the trunnions as the snap hinge is inserted downward into the snap socket, the trunnions will deflect the cantilever members resiliently away from the snap hinge until the trunnions pass the cantilever members, allowing the cantilever members to flex inward toward one another so as to capture the trunnions and retain the snap hinge in the snap socket and to hold the snap hinge generally centered in the snap socket; so that to open the container, the left and right panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, the front and rear panels will be pivoted from a folded position lying generally flat adjacent the base, to an upright position, and at the same time will be raised upward so that the fingers of the front and rear panels will be juxtaposed over corresponding pockets of the left and right panels, the front and rear panels will be lowered so that the fingers will be received in the pockets, thereby latching the panels at the edges thereof in the open position; a plurality of feet extending downward from the base to a bottom surface so as to raise the container off a floor, the feet having an outer edge with a shoulder adapted to receive the top edges of the front, rear, left, and right panels when the container is open, and to receive the base wall when the container is folded, so as to enable containers to be stacked one upon another in both the open and closed positions; and a plurality of skid bars attached to the bottom surface of the feet, the skid bars having a cross-sectional shape, each of the feet having a shape in its bottom surface matching the cross-sectional shape so as to receive the skid bars.
 18. The collapsible container of claim 17, further comprising: front and rear access doors extending between opposite outer edges and between opposite top and bottom edges, the front and rear access doors each having inner and outer surfaces, the outer edges each having a plurality of plugs arrayed in a linear spaced relationship along the outer edges; the front and rear panels each having an access opening extending between opposite outer edges and between a lower edge and the panel top edge, each access opening having a plurality of receptacles arrayed in a linear spaced relationship along the outer edges, the receptacles being adapted to receive the plugs; and door pivotal means for pivotal mounting of the front and rear access doors on the front and rear panels, respectively, the door pivotal means providing lost motion; so that the front and rear access doors will be pivoted downward into an open position adjacent the front and rear panels respectively, and depending from the access opening lower edge, and will be pivoted upward into an upright closed position in the access opening, with the plugs juxtaposed over the receptacles, and will be lowered until the plugs are received in the receptacles, thereby latching the access doors closed.
 19. The collapsible container of claim 18, wherein the door pivotal means further comprises: a first row of hinge knuckles arrayed in a linear spaced relationship along the front and rear panels access opening lower edges, the first row of hinge knuckles having passages therethrough in linear alignment defining a first door axis; a second row of hinge knuckles arrayed in a linear spaced relationship along the front and rear access doors bottom edges, the second row of hinge knuckles having passages therethrough in linear alignment defining a second door axis; a front link and a rear link, each link having a third row of hinge knuckles arrayed in a linear spaced relationship along the link, the third row of hinge knuckles having passages therethrough in linear alignment defining a third door axis, each link having a fourth row of hinge knuckles arrayed in a linear spaced relationship along the link, the fourth row of hinge knuckles having passages therethrough in linear alignment defining a fourth door axis, the third door axis and the fourth door axis being parallel and spaced apart, the third and fourth rows of hinge knuckles being adapted to fit between the first and second rows of hinge knuckles, respectively, with the first door axis collinear with the third door axis, and the second door axis collinear with the fourth door axis; and two hinge rods for each link, the hinge rods being straight and of a uniform predetermined radius adapted for close sliding engagement with the first, second, third, and fourth hinge knuckle passages, each hinge rod having a locking member at one end, the locking member protruding beyond the predetermined radius, so as to wedge tightly in the hinge knuckle passages, thereby retaining the hinge rods in the hinge knuckles.
 20. The collapsible container of claim 18, wherein the base, front panel, rear panel, left panel, right panel, front access door, and rear access door are molded from a polymeric material selected from the group consisting of thermoplastic resins and thermoset resins.
 21. The collapsible container of claim 17, further comprising a bumper plate mounted on the outer edge of each of four of the feet at the corners of the base, the bumper plate being generally L-shaped and extending between opposite upper and lower edges, the bumper plate having an inner surface for mounting against the feet, and an opposite outer surface, the bumper plate having a flange extending outward and downward from the lower edge, the flange being adapted to overlap an adjacent lower stacked container, so as to prevent lateral shifting of a stacked container. 